Note: This was originally published as “Placebo, es-tu là?” in Science et pseudo-sciences 294, p. 38-48. January 2011. It came to my attention in the course of an e-mail correspondence with the editors of that magazine, where one of my own articles was published in French translation in January 2015. I thought this was the best explanation of placebo that I had ever read. It covers the same points my colleagues and I have addressed and more. It describes the pertinent research and uses particularly effective graphs to illustrate the principles (a picture is worth a thousand words). The author, Jean Brissonnet, kindly gave his permission for me to translate it and share it with our readers.

In fact, you don’t need to give a placebo to get a placebo effect and therefore we can now think about how we can maximize the placebo component of routine care.

~ Damien Finniss, 2010

The scene takes place in a surgical suite where they are preparing to do a cataract operation. The patient is lying on the operating table. A few minutes earlier the anesthetic gel was applied to the cornea to permit an operation under simple local anesthesia. The surgeon arrives in the company of the anesthetist. They are engaged in a spirited discussion and don’t seem to be agreeing.

“It has been proven,” says the surgeon, “that 30% of the action of a medical treatment is due to the placebo effect.”

“I doubt that,” retorts his interlocutor, “I think that placebo story is one of those medical myths on a par with the idea that we only use 10% of our brain, that nails and hair grow after death, or that cellphones create interference in hospitals.”[1]

“No,” insists the surgeon with a superior tone, “the fact is established and has been proven by numerous studies.”

The anesthetist shakes his head with a slight smile, but he doesn’t reply. As for the patient, who might have much to say on the subject, he keeps quiet, because it would not be prudent to argue with someone who is about to suck the lens out of your eye.

This true anecdote would not be of interest if it didn’t concern two members of the medical profession. Why such uncertainty? Why such lack of knowledge about such a fundamental subject? This faith in an all-powerful, magical, and mysterious placebo is common among the general public and it serves as justification for resorting to unconventional medicines that have never been able to show solid proof of efficacy; but we see that it still persists among the medical profession.

To know whether the placebo effect is real or should be relegated to the same category as poltergeists, it will help to go back in history.

Perhaps the most pervasive medical conspiracy theory of all involves stories that there exist out there all sorts of fantastic cures for cancer and other deadly diseases but you can’t have them because (1) “they” don’t want you to know about them (as I like to call it, the Kevin Trudeau approach) and/or (2) the evil jackbooted thugs of the FDA are so close-minded and blinded by science that they crush any attempt to market such drugs and, under the most charitable assessment under this myth, dramatically slow down the approval of such cures. The first version usually involves “natural” cures or various other alternative medicine cures that are being “suppressed” by the FDA, FTC, state medical boards, and various other entities, usually at the behest of their pharma overlords. The second version is less extreme but no less fantasy-based. It tends to be tightly associated with libertarian and small government fantasists and a loose movement in medicine with similar beliefs known as the “health freedom” movement, whose members posit that, if only the heavy hand of government were removed and the jack-booted thugs of the FDA reined in, free market innovation would flourish, and the cures so long suppressed by an overweening and oppressive regulatory apparatus would burst the floodgates. Under this views, these cures, long held back by the dam of the FDA, would flow immediately to the people, and there would be much rejoicing. (Funny how it didn’t work out that way before the Pure Food and Drug Act of 1906.) Of course, I can’t help but note that in general, in this latter idea, these fantastical benefits seem to be reserved only for those who have the cash, because, well, the free market fixes everything. At least, that seems to be the belief system at the heart of many of these conspiracy theories.

The idea that the FDA is keeping cures from desperate terminally ill people, either intentionally or unintentionally, through its insistence on a rigorous, science-based approval process in which drugs are taken through preclinical work, phase 1, phase 2, and phase 3 testing before approval is one of the major driving beliefs commonly used to justify so-called “right-to-try” laws. These bills have been infiltrating state houses like so much kudzu, and the Ebola outbreak has only added fuel to the fire based on the accelerated use of ZMapp, a humanized monoclonal antibody against the Ebola virus, in some patients even though it hadn’t been tested in humans yet (more on that later). Already four of these laws have been passed (in Colorado, Missouri, Louisiana, and now Michigan) with a referendum in Arizona almost certain to pass next week to bring the total to five states with such laws. Basically, these laws, as I’ve described, claim to allow access to experimental drugs to terminally ill patients with a couple of major conditions: First, that the drug has passed phase I clinical trials and second that the patient has exhausted all approved therapies. As I’ve explained before more than once, first when the law hit the news big time in Arizona and then when a right-to-try bill was introduced into the legislature here in Michigan, they do nothing of the sort and are being promoted based on a huge amount of misinformation detailed in the links earlier. First, having passed phase 1 does not mean a drug is safe, but right-to-try advocates, particularly the main group spearheading these laws, the Goldwater Institute, make that claim incessantly. Second, they vastly overstate the likelihood that a given experimental drug will help a given patient. The list goes on.(more…)

Although obscured by controversy, there is evidence to indicate that spinal manipulation can be as effective as conventional treatment methods in relieving low-back pain.1,2,3,4 This grain of truth mixed with chiropractic vertebral subluxation theory that encompasses a broad scope of ailments makes it difficult for the average person to distinguish between appropriate and inappropriate use of manipulation by chiropractors. A person who is satisfied with chiropractic manipulative treatment for back pain might be led to believe that the same treatment can be used to treat a variety of organic ailments by correcting “vertebral subluxations.” Such treatment is usually described as a “chiropractic adjustment.”

A manual chiropractic adjustment

Although chiropractic care based on subluxation theory has been rejected by the scientific community, spinal manipulation used in the treatment of mechanical-type back pain has a plausible basis that makes it acceptable in mainstream healthcare. A good back-cracking back rub provided by a chiropractor or some other manual therapist can be a pleasurable, pain-relieving experience, and this can be a preferred method of treatment for some types of back pain. But you should be well-informed enough to know where to draw the line in separating subluxation-based chiropractic adjustments from appropriate use of generic spinal manipulation if you should consider treatment by a chiropractor. Otherwise, you might become the victim of the bait-and-switch tactics of chiropractors who offer you treatment for back pain and then attempt to indoctrinate you in subluxation theory.

Much of what follows in this article has been said before in other articles of mine posted on this site. An up-to-date summary of basic concerns about chiropractic care, however, might be useful for new readers and others, including professionals, who want a brief overview for quick reference in seeking answers to questions about the problematic aspects of chiropractic use of spinal manipulation.(more…)

Three weeks ago, I mentioned in a post that the week of October 7 to 14 was declared by our very own United States Senate to be Naturopathic Medicine Week, which I declared unilaterally through my power as managing editor of Science-Based Medicine (for what that’s worth) to be Quackery Week. One wonders where the Senate found the time to consider and vote for S.Res.221, which reads:

S.Res.221 – A resolution designating the week of October 7 through October 13, 2013, as “Naturopathic Medicine Week” to recognize the value of naturopathic medicine in providing safe, effective, and affordable health care.

I know, I know, it probably took all of five minutes to consider and vote for this, thanks to Sen. Barbara Mikulski (D-MD), who sponsored it. In any case, as October 7 approached, I thought about how I could keep my promise to blog about naturopathy this week, and I came up with a way to do it. It’s a bit roundabout, but I think it fits. The idea derives from a discussion I was having a while back about one of my “favorite” hospitals, namely the Cancer Treatment Centers of America, in which a colleague of mine questioned why there were so many CTCA ads on NPR and why CTCA is sponsoring shows on PBS such as the upcoming The Emperor of All Maladies by Ken Burns. Although I can’t wait to see this particular series, I am a bit worried that the infiltration of quackademic medicine will make an appearance, given that CTCA is a major sponsor. (more…)

Science journalist Sharon Begley wrote a recent piece in The Saturday Evening Post about Placebo Power. The piece, while generally better than the typical popular writing on placebos, still falls into the standard placebo narrative that is ubiquitous in the mainstream media. The article is virtually identical to a dozen other articles I have read on placebo effects in the popular press, and most significantly fails to even question that narrative.

Begley is generally one of the better science journalists, although I have had my disagreements with her – specifically over her attitude toward the relationship between skeptics and the media. She seems to have a distorted and negative view of skeptics and does not think that the media can or should help us in our “debunking crusade.” (The term itself speaks of a fundamental misunderstanding of the modern skeptical movement.)

I have also parted ways with Begley over her view of the relationship between science and medicine. She seems to have a fairly negative view of doctors, fueled in part by her imperfect grasp of medical science. This is the risk with even the best lay science journalists – science is often complex and it is difficult to master the nuances if you are not an expert and steeped in the evidence and the community. Further there is a tendency for people in general (including journalists) to go along with an appealing and available narrative. (For journalists those narratives that are appealing are the ones that make good headlines.) These shortcomings are present throughout her recent article on placebos.

Researchers are increasingly trying to tease apart the various components of “the placebo effect.” In reality we should use the term “placebo effects” as it is demonstrably multifactorial. “The placebo effect” really refers to whatever is measured in the placebo arm of a clinical trial – everything other than a physiological response to an active intervention. Within that measured response there are many potential factors that would cause an outcome from a fake treatment to be different from no treatment at all. These include statistical effects like regression to the mean and the natural course of symptoms and illness, reporting bias on the part of the subject, and a non-specific response to the therapeutic interaction with the practitioner.

It is also critical to realize that placebo responses vary greatly depending on the disease or symptom that is being treated and the outcome that is being measured. Placebo response is greatest for subjective symptoms of conditions that are known to be modified by things like mood and attention, while it is virtually non-existent for objective outcomes in pathological conditions. So there is a substantial placebo response for pain and nausea, but nothing significant for cancer survival.

I realize that Steve blogged about this study earlier in the week, but since I also commented on this particular study as my not-so-super-secret alter ego, I figured it rated a place on SBM as well. I emphasized different aspects of the study and tried to quantify exactly why, under even the most charitable interpretation of the study possible, the effects are not clinically significant. Besides, if the level of comments and e-mails is any indication, there is sufficient interest in this particular study to rate a second post.

Not suprisingly, this study is about about acupuncture. Well, it’s not exactly a study, it’s a meta-analysis that aggregates a whole lot of acupuncture studies in which this most popular of woos is administered to patients with chronic pain from a variety of causes. It’s also being promoted all over the place with painfully credulous headlines like:(more…)

I don’t know how I’ve missed this, given that it’s been in existence now for a month and a half, but I have. Regular readers (and even fairly recent readers, given that I write about this topic relatively frequently) know that I’m not a big fan of the National Center for Complementary and Alternative Medicine (NCCAM). (Come to think of it, neither is anyone else writing for this blog.) Just search this blog for “NCCAM” if you don’t believe me. I’ve explained the reasons many times, but the CliffsNotes version is that NCCAM is an enormous waste of taxpayer money, dedicated as it is to the study of modalities that are at best highly implausible and at worst break well-established laws of physics (i.e., “energy healing”). I do concede that, since the latest NCCAM director (Dr. Josephine Briggs) took over, there has been a noticeable attempt to bring more scientific rigor to NCCAM, and to some extent Dr. Briggs has succeeded. At the very least she is a legitimate scientist with an impressive pre-NCCAM track record, and I do fear who will succeed her when she moves on or retires given that there is enormous pressure from the CAM community to appoint one of their own as director.

Unfortunately, as rigorous a scientist as Dr. Briggs was in her former life, since coming to NCCAM she has gradually been assimilated into the culture of the place. Indeed, although it is good that NCCAM has backed away from studying woo like homeopathy and distance healing, the co-optation of science-based modalities such as exercise, diet, and natural products pharmacology has continued apace. Worse, the recently released five year strategic plan for NCCAM admitted that the science funded by NCCAM in the past was crap and, in essence, promised to do some real science for a change. That’s why on occasion I’ve jokingly said that we should take off and nuke NCCAM from orbit. It’s the only way to be sure. On the other hand, no doubt someone would think I seriously mean that we should nuke NCCAM. Of course, I’d never advocate that! NCCAM is located right smack dab in the middle of the NIH campus. The collateral damage would be unacceptable.

We have learned that verbal suggestions can activate neurotransmitters and modulate pain perceptions, and positive expectations can activate endogenous opioid and cannabinoid systems. A complex mental activity has objective effects on body physiology. Words and drugs can activate the same mechanisms. Drugs are less effective without therapeutic rituals. We are delving deep into human foibles and vulnerable traits at the center of human interactions. What implications do these insights into mind-body interactions have for patient care?

Last week, I discussed a rather execrable study. Actually, the study itself wasn’t so execrable, at least not in its design, which was a fairly straightforward three-arm randomized clinical trial. Rather it was the interpretation of the study’s results that was execrable. In brief, the authors tested an “energy healing” modality known as “energy chelation” versus a placebo (sham “energy chelation”) and found, as is so often the case in studies of “complementary and alternative medicine” (CAM) or “integrative medicine” (IM) that both modalities did better than no treatment on the primary outcomes but that the “real” treatment (if one can call energy chelation “real treatment”) produced outcomes that were statistically indistinguishable from the “sham” treatment. Not surprisingly, the next move on the part of the researchers was to do a bunch of comparisons, and, as is so often the case (particularly when one fails to correct statistically for multiple comparisons), they found a couple of secondary endpoints with barely statistically significant differences and trumpeted them as meaning that their “energy chelation therapy” has “significant promise for reducing fatigue.” They then argued that the study was also ” designed to examine nonspecific and placebo elements that may drive responses.”

Which brings us to the “power” of placebo.

As I was contemplating what I wanted to discuss this week, I thought about the study that Drs. Coyne, Johansen, and I objected to, but then I also thought about Dr. Crislip’s post last week and post I did about a month ago in which I noticed how lately CAM apologists seem to be—shall we say?—retooling their message in the wake of negative trial after negative trial of their implausible treatments. Gone (mostly) are claims of powerful specific effects and efficacy from treatments such as various “energy healing” modalities, acupuncture, homeopathy, and the like themselves, to be replaced by claims that physicians should embrace CAM because it’s “harnessing the power of placebo” to produce “powerful mind-body healing.” It’s a powerful message that has sucked in people who normally would be considered skeptics, such as Michael Specter, who, as I described, apparently bought into the message sufficiently that when Ted Kaptchuk was making the media round right before the holidays he happily published a fairly credulous interview with him entitled, The Power of Nothing: Could Studying the Placebo Effect Change the Way We Think About Medicine? (My answer: Very likely no.) Even Ira Flatow of Science Friday fell hard for Kaptchuk’s message, declaring at the beginning of the interview that Kaptchuk’s irritable bowel syndrome study is evidence that “placebos work even when patients are in on the secret.” (It’s not.)

That skeptics and scientists find the idea that the mind has the power to heal the body, often referred to as “self-healing” or “mind-body healing,” so seductive should probably not be surprising. After all, who wouldn’t want to be able to cure themselves simply by willing it to be so? It’s a concept that, like so many concepts in CAM, goes far back into ancient times and stretches forward to today in ideas like The Secret, which goes quite a bit beyond the whole idea of “mind-body healing” or healing yourself because you wish it to be so, and declares that you can have virtually anything you want simply by thinking the right thoughts. In fact, to me it appears that the “powerful placebo” is being drafted in the service of supporting what are, at their core, mystical beliefs far more than science. I’d like to elaborate on that idea a bit more than I did last time I discussed this isssue, where I concluded by writing:

In the end, all too much of the rebranding of CAM as placebo and the selling of placebos as some sort of powerful “mind-body healing” strikes me as being much like The Secret, in which wishing makes it so.